The correct option is B Remain unchanged
Mitosis is the process of cell division wherein the chromosomes replicate and gets equally distributed into two daughter cells. The chromosome number in each daughter cell is equal to that in the parent cell, i.e., diploid. Hence, mitosis is known as equational division. Once mitosis is complete, the cell has two sets of 46 chromosomes, each enclosed with their own nuclear membrane. The cell then splits in two by a process called cytokinesis, creating two clones of the original cell, each with 46 monovalent chromosomes. So, the number of chromosomes remain unchanged in mitosis.
So, the correct option is C.